African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5182

Full Length Research Paper

Regulation of the bE and bW genes in Sporisorium scitamineum using silver nanoparticles synthesized with Carissa spinarum extract

Bongani Z. Nkhabindze
  • Bongani Z. Nkhabindze
  • Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Science, Technology and Innovation (PAUISTI), Nairobi, Kenya.
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Elijah M. Ateka
  • Elijah M. Ateka
  • Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic Science, Technology and Innovation (PAUISTI), Nairobi, Kenya.
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Diana M. Earnshaw
  • Diana M. Earnshaw
  • Crop Production Department, Faculty of Agriculture, University of Eswatini, Luyengo, Eswatini.
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Harrison N. Wanyika
  • Harrison N. Wanyika
  • Department of Chemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
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  •  Received: 08 September 2022
  •  Accepted: 14 October 2022
  •  Published: 31 October 2022

Abstract

Sugarcane smut is caused by the fungus Sporisorium scitamineum. It is a disease of economic importance in the sugarcane industry because it can cause losses that can lead to total crop failure. Bio-synthesized silver nanoparticles have been found to possess antimicrobial properties, yet they have not been explored against S. scitamineum. Optimization of the mixtures using ultraviolet-visual spectroscopy (UV-Vis) showed peaks in the range of 340 to 400 nm. The Fourier transform infrared spectroscopy (FTIR) analysis identified proteins as essential capping agents, and reducing sugars were responsible for reducing the silver nitrate to nanoparticles and stabilizing the nanoparticles.  They have the highest antifungal activity at 5 mg/ml, while the minimum inhibitory and fungicidal concentrations were 0.078 mg/ml. The in-vivo assays showed a significant (P<0.05) reduction of the pathogen biomass in plants treated with the nanoparticles compared to the control plants. The application of 0.0585 mg/ml of the nanoparticles to the S. scitamineum resulted in a significant (P<0.05) increase in the expression of the bE and bW genes. Silver nanoparticles that were synthesized using C. spinarum crude extract inhibited the growth of S. scitamineum both in-vitro and in-vivo and had a regulatory effect on the expression of the pathogenicity genes in the fungus.

 

Key words: Sporisorium scitamineum, sugarcane smut, Carissa spinarum, biosynthesized silver nanoparticles, antifungal activity.